> The problem with the "???" step is that it's unrigorous handwaving.
Probably because nobody actually knows right now what actually causes the differences and how. The case that is caused exclusively by entrenched sexism - somehow driven by people graduating from the same institutions who have been fighting sexism for decades now, and by the same people who repudiate and denounce sexism on every corner - also does not sound very convincing. Sexists, of course, do exist, so does sexism, but presenting it as sole driver and concluding any deviation from 50% or whatever the population demographics would be is the ironclad indicator for sexism is as "unrigorous handwaving" as the opposite extreme.
Probably because nobody actually knows right now what actually causes the differences and how. The case that is caused exclusively by entrenched sexism - somehow driven by people graduating from the same institutions who have been fighting sexism for decades now, and by the same people who repudiate and denounce sexism on every corner - also does not sound very convincing. Sexists, of course, do exist, so does sexism, but presenting it as sole driver and concluding any deviation from 50% or whatever the population demographics would be is the ironclad indicator for sexism is as "unrigorous handwaving" as the opposite extreme.